The dumbo rat mutant: a cytogenetic, morphologic and sagittal morphometric analyzis.


  • Stéphane M Louryan Université Libre de Bruxelles
  • Suhair Katerji Université Libre de Bruxelles
  • Marcel Rooze Université Libre de Bruxelles
  • Nathalie Vanmuylder Université Libre de Bruxelles


Study the possibility of use Dumbo rat as, experimental model for understanding abnormal craniofacial development investigated craniofacial morphogenesis in the Dumbo rat by morphologic and morphometric technics. We also performed a cytogenetic study of this rat. Wistar strain was considered as control. For morphologic and morphometric studies, we used Dumbo and Wistar embryos at E15 to 21. We stained these embryos emin toto/em with alcian blue and alizarin red. The skeletons of the embryos were examined and drawn under a Lucida camera, and the following sagittal measurements were taken: zygomatic length and thickness, length of the mandible and its anterior and posterior thicknesses, length of the maxillary, and petrous bone height. Statistical analyses were realized using Mann Whitney test in SPSS. For study, chromosome spreads were prepared from lymphocyte cultures obtained from the blood of adult rats of both strains. Dumbo embryos exhibed hypoplasia of the zygomatic, maxillar and mandibular bones, and micrognathia, evoking some human dysmorphogenesis . Moreover, the position of the preliminary ear was abnormally low. The differences in the measurements of the craniofacial structures between the two groups of rats are significant did not reveal any differences between the two strains.

Conclusion: our data indicate that the considerable morphometric differences between the craniofacial structures of Dumbo and Wistar rats might be due to genetic mutations that are undetectable by chromosome mapping. Further histologic and genetic analyses might contribute to elucidate the early determinism of the Dumbo phenotype.

Author Biography

Stéphane M Louryan, Université Libre de Bruxelles

Department of anatomy, biomechanics and organogenesis. Full professor






Original Research Articles